import { Directive, DirectiveBinding,nextTick } from 'vue'
const loadMore: Directive = {
  beforeMount(el: any, binding: DirectiveBinding) {
    const selectDom = (document.querySelector(".more_select_dropdown") as any).querySelector(".el-select-dropdown .el-select-dropdown__wrap");
    function loadMores(this: any) {
      const isBase = this.scrollHeight - this.scrollTop <= this.clientHeight
      if (isBase) {
        binding.value && binding.value()
      }
    }
    el.selectDomInfo = selectDom
    el.userLoadMore = loadMores
    nextTick(() => {
      selectDom?.addEventListener('scroll', loadMores)
    })
  },
  beforeUnmount(el: any) {
    if (el.userLoadMore) {
      el.selectDomInfo.removeEventListener('scroll', el.userLoadMore)
      delete el.selectDomInfo
      delete el.userLoadMore
    }
  }
}
export default loadMore